Ransom.Win32.ENMITY.THJOFBC
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It drops files as ransom note.
TECHNICAL DETAILS
Arrival Details
This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Ransomware drops the following files:
- {Drive Letter}:\KeyForFiles\Key.secret → contains encrypted victim's information and master key for decryption
- {Drive Letter}:\KeyForFiles\DecryptionKey.txt
- C:\KeyForFiles\PublicKey.txt
- E:\Rns for being rich\Enmity\Release\Enmity.pdb → project file
Other System Modifications
This Ransomware adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Enmity
ID = {Victim's ID}
Information Theft
This Ransomware accepts the following parameters:
- {Drive Letter}:\
Other Details
This Ransomware does the following:
- Upon execution, it shows a command line interface whereas it accepts parameters:
- 1 → Full Encryption
- 2 → Specific Directory Encryption (note that the sample file should be in the directory to be encrypted)
- The information inside the Key.secret file for decryption are the following:
- Victim ID
- Amount of data Encrypted
- Criminal email address
- IP address
- Date of Infection
Ransomware Routine
This Ransomware renames encrypted files using the following names:
- {Random}-Mail[{BLOCKED}o@gmail.com ]ID-[{User's ID}].{Random 6-byte characters}
It drops the following file(s) as ransom note:
- Enmity-Unlock-Guide.txt
SOLUTION
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
-
PE.Win32.TRX.XXPE50FFF074
Step 2
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 3
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 4
Search and delete this file
- C:\KeyForFiles\Key.secret
- C:\KeyForFiles\DecryptionKey.txt
- C:\KeyForFiles\PublicKey.txt
- E:\Rns for being rich\Enmity\Release\Enmity.pdb
Step 5
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Enmity
- ID = {Victim's ID}
- ID = {Victim's ID}
Step 6
Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.ENMITY.THJOFBC. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check the following Trend Micro Support pages for more information:
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